In connection with shipping products, such as food products, from a manufacturer to a retail establishment, it is known to package the products in a carton, seal the carton, and ship the carton for delivery to a designated retail establishment. Although various materials could be used in making the cartons, the most common material employed is paperboard. In general, the paperboard is provided in the form of a blank which can be conveniently stored in a flat configuration but easily erected through a simple folding operation to establish an open-ended carton which can be filled and sealed, typically in an automated process. These cartons are not only lightweight and quite strong, but the paperboard is advantageously recyclable.
In some situations, the cartons are designed with a closure system which enables the carton to be opened and closed numerous times prior to depleting the products therein. For example, it is widely known to package cereal and other food products in end load cartons and to provide the cartons with closure systems operating between upper and lower flaps of top portions of the cartons. After this type of carton is initially unsealed, a tab projecting from the upper flap is designed to be slipped into a slot provided in the lower flap in order to re-close the carton for future access. However, it is not uncommon for a user to initially detach the upper and lower flaps by grasping the tab and pulling on the tab in attempting to overcome adhesive forces securing the upper and lower flaps. Unfortunately, this manner of opening the carton often leads to the tab being torn, thereby rendering the closure system unsatisfactory or even unsuitable for reclosure purposes. In fact, a common design actually provides for the tab extending from the remainder of the upper flap through obtuse angles, with the flap typically tearing at the vertexes of these angles.
A known prior art arrangement of this type is represented in FIGS. 1-3 wherein FIG. 1 shows an open ended carton 5 including a top portion 10 having an upper flap 15 adhered to a lower flap 20 such as in a sealed, shipping state. Upper flap 15 is formed with a central tab 25 which is provided for reclosure purposes and essentially established by forming a pair of generally V-shaped cutouts 30 and 31 at spaced locations along a free edge 35 of carton 10. Most often, a carton formed in this fashion is initially sealed with adhesive extending below end regions 40 and 41 of upper flap 15. As indicated above, it is quite common for a user to initially peel up tab 25, grip the same, and pull up on tab 25 in an attempt to separate upper flap 15 from lower flap 20. However, the adhesive can be quite strong, often leading to the area associated with tab 25 ripping from each vertex 45 associated with the cutouts 30 and 31 a substantially portion of upper flap 15 as represented by the tear lines 47 and 48 in FIGS. 2 and 3. When this occurs and tab 25 is later used to reclose open ended carton 5 through insertion into a slot 50 formed in lower flap 20, end regions 40 and 41 are really not pressed against lower flap 20 as intended, as represented in FIG. 3.
In addition to the above, prior known closure systems of this type are not considered to be particularly advantageous for use with individuals of all ages and levels of ability. For instance, individuals suffering from arthritis of the hands can find it particularly difficult to manipulate the tab in combination with the slot in repeatedly opening and closing such a carton. In any case, in light of these and other drawbacks, it would be desirable to provide an open end carton with a closure system which is at least significantly less prone to tearing and can be readily utilized by individuals of varying ages and abilities. In addition, it would be desirable to provide a closure system for an open ended carton wherein the system feels, and potentially even sounds, more secure than prior known systems, thereby providing a tactical feedback which can convey a sense of confidence to the user regarding the effectiveness of the closure system.